I need some help for my appleScript.

For all open windows, I want to know which one is hidden (in the dock), which one is visible and which one is focused?

To list windows I use :

tell application "System Events"
    set procs to processes
    set windowName to {}
    repeat with proc in procs
        try
            if exists (window 1 of proc) then
                repeat with w in windows of proc
                        copy w's name to the end of windowName
                end repeat
            end if
        end try -- ignore errors
    end repeat
end tell
return windowName

I tried focused property:

copy w's focused to the end of windowName

and selected property:

copy w's selected to the end of windowName

But this doesn't work!

Thanks for help!